Anxious teen? This could be part of it
A new study out of Weill Cornell Medical College has shown that when a threat hits a teen's brain, they can't make the fear disappear like adults can. This ability is called fear extinction learning, and researchers believe that teens' lack of fear extinction learning may be what causes much of the anxiety and stress so often present during the teen years. In fact, one of the researchers said that anxiety disorders tend to spike during or just before adolescence.
Another of the researchers explained that neurons that help with fear extinction (realizing that something that once scared them is no longer a danger) are less active in adolescents (mice, in this case). This also means that desensitization techniques (like having someone who is afraid of snakes hold a snake) may not work on teens as well.
In this study, the found that young and old mice have plasticity in the infralimbic prefrontal cortex, but not the teen mice.
Here's the study: